Fix build.

.travis.yml

@@ -1,25 +1,55 @@
+dist: xenial
+
+addons:
+  apt:
+    packages:
+      - ant-optional
+
 language: php
 
 php:
-  - "5.6"
-  - "7.0"
+  - "7.3"
+  - "7.2"
   - "7.1"
+  - "nightly"
 
 env:
+  - CONTAO_VERSION=~4.6.0
+  - CONTAO_VERSION=~4.5.0
   - CONTAO_VERSION=~4.4.0
 
-sudo: false
-
-before_install:
-  - phpenv config-add travis.php.ini
+# Exclude impossible Contao Version combinations.
+matrix:
+  exclude:
+  allow_failures:
+    - env: CONTAO_VERSION=~4.6.0
+    - env: CONTAO_VERSION=~4.5.0
 
-install:
+before_script:
+  - echo "memory_limit=-1" >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini
   - travis_retry composer self-update && composer --version
-  - travis_retry composer require contao/core $CONTAO_VERSION --no-update
-  - travis_retry composer update --prefer-dist --dev --no-interaction
+  - travis_retry composer require contao/core-bundle $CONTAO_VERSION --no-update
+  - >
+    if [ "x${TRAVIS_TAG}" != "x" ]; then
+      export COMPOSER_ROOT_VERSION=${TRAVIS_TAG}
+    else
+      export COMPOSER_ROOT_VERSION=$([[ ${TRAVIS_BRANCH} =~ hotfix/([0-9.]*(-(alpha|beta|rc)[0-9]+)?) ]] \
+        && echo ${BASH_REMATCH[1]} \
+        || echo dev-${TRAVIS_BRANCH})
+    fi
+  - echo "Using root version ${COMPOSER_ROOT_VERSION}"
+  - travis_retry composer update --prefer-dist --no-interaction
 
 script: ant -keep-going
 
-# Hack to make the repo non shallow - we can not use a shallow repository.
+# Hack to make things work again - we can not use a shallow repository.
 git:
   depth: 2147483647
+
+branches:
+  except:
+    - /.*-translation/
+
+cache:
+  directories:
+    - vendor

composer.json

@@ -32,6 +32,7 @@
     "contao/core-bundle": "^4.4"
   },
   "require-dev": {
+    "contao/manager-plugin": "^2.1",
     "phpcq/all-tasks": "~1.1"
   },
   "autoload": {